Latch mechanism



Nov.. 27, 1934.V

A. MICHAUKA LATCH MEGHANISM Filed June 27, 1953 WITNES Patented Nov. 27, 1934 UNITED VSTATI-:s lP.A.'.1s1\rr OFFICE LATCH MEomrNIsMy Anthony Michauka, Chicago, Ill. Application June 27, 1933, serial No. 677,948

7 Claims.

This invention relates to certain novel improvements in latch mechanisms, and has for its principal object the provision of an improved construction of-this character which will be highly efficient in use and economical in manufacture.

Another object of the invention is to provide an improved door latching mechanism.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangements of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawing, showing the preferred form of construction and in which:

Fig. 1 is a fragmentary plan View of my invention depicting the same in applied position;

Fig. 2 is a front elevational view of my invention taken substantially on the line 2-2 in Fig. 1;

Fig. 3 is a side elevational view of my invention taken substantially on the line 3-3 in Fig. 2;

Fig.4 is a side elevational View of my invention taken substantially on the line 4-4 in Fig. 2;

Fig. 5 is atransverse sectional view of my invention taken substantially on Fig. 2; and

the line 5-5 in Fig. 6 is an elevational View of the key employed in connection with my invention.

The new latch mechanism is generally indicatedl at 10 in the drawing and is enclosed in a casing l which is attached to the inner side of a door 12. The latch mechanism lincludes a latch bolt 13 which has an end portion 40 adapted for latching engagement in a slot 39 formed in a keeper 14 attached `to the door easement 15.

Slidably mounted on and guided by means of pin and slot connections 16, for movement axially along the latch bolt 13, is an auxiliary latch member in the form of a plate 17 which has a rack of teeth 18 formed along its lower edge.

This

plate 17 has a pointed end portion 38 that is adapted to be projected into the slot 39 formed in the keeper plate 14.

key sockets or recesses 22 for the reception of prongs 23 that are formed on a latch operating key 24.

A vertical screw 25 is mounted in the casing 1l and has a yoke 26 at its upper end which receives 'the latch bolt 13.

This screw 25 carries a horizontal gear 27 which meshes with a second horizontal gear 28 and this gear 28 has a" beveled edge 29 which meshes with a beveled edge 30 on a vertical gear 31.

The gear 31 has (c1. *zo-29) a second beveled edge 32 which meshes with a beveled edge 33 of a spur gear which meshes with a vertical gear 35. The gear 35vis coaxially mounted relative to but rotatable independently of the'gear 21 (Fig. 4). f

Formed in the gear 35 coaxially with the key slots 22 is a key slot 36 for the reception of the non-circular stem 37 of the latch key 24.

This device operates as follows. When the parts are in latched position (Fig. 2) both the pointed latchingend portion 38 of the slide ,plate 17 and the latching end portion of the slide bar or bolt 13 are projected into the slot 39 in the keeper plate 14, Vthe pointed end` portion 38 being projected above the latching end portion 40 of the latch bolt 13, thereby preventing the latch bolt 13 from being lifted or raised by an unauthorized person inserting an implement between the keeper member 14 and the casing 11. This is the principal purpose and advantage ofthe slide plate 17 and its end portion. `f

To raise and unlatch or retract the latch bolt f 13 the end portion 38 of the slide plate 17 must iirst be retracted from the slot 39 and this is accomplished by inserting the projecting prongs 23 of the key 24 into the recesses 22 formed in the gear 21. The key 24 is then rotated (clockwise as seen looking rearwardly in Fig. 2) thereby rotating the gear 21 and transmitting movement through the gears 20 and 19 to the rack 18 to move the latter to the left (Fig. 2),thereby retracting the latching end portion 38 of the slide plate `17 out of theaperture or slot 39 in the keeper 14 to permit the latch bolt 13 to be lifted, which is accomplished as follows:

After the latch slide plate 17 has been moved to retractthe end portion 38 thereof out Lof the slot 39 in the keeper 14 thelatching end portion 40 of the latch bolt 13 is lifted, to permit the door 12 to be slid open (to the left, Fig. 1) by inserting the end portion 37 of the key 24 into the socket 36 andturning the key 24 to the right (clockwise, lookingrearwardly in Fig. 2) thereby imparting motion through the gear train 35`3433-`3231--30--29--28-27 `to the screw 25 and its yoke 26 to lift the latter and raise the latching end portion 40 of the vbolt 13 out of latched engagement in the keeper slot 39.

To hold the latch bolt 13 in retracted or ineffective position and to prevent accidental latching ofthe same when desired to keep the door 12 unlatched a cam slot 41 is provided in the latch bolt 13 and a pin 42 projects from the rear wall of casing 11 into this slot 41. To effect this result the latch bolt 13 is pulled forwardly (to the right,

Fig. 2)` until the pin 42 enters the lower branch of the slot 41 whereupon the latch bolt is pulled rearwardly (to the left, Fig. 2) until the pin 42 enters the angled end portion 43 of the slot 41, in which position the pin 42 prevents the latch bolt 13 from being accidentally or unintentionally slipped forward (to the right, Fig. 2) into latched position.

While I have illustrated and vdescribed the preferred form of construction for carrying my invention into effect, this is capable of variation and modication, without departing from the spirit cf the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention what I claim as new and desire to protect by Letters Patent is:

1. In a door latching mechanism, the combination of a latch bolt adapted to be slidably mounted on a door and having an end portion arranged for projection into latching engagement with a keeper member arranged on a door casement, a screw member having a portion bearing under said bolt to lift the same out of latching engagement with said keeper member, a gear carried by said screw member, and a gear train for opkey to operate said gear train.

2. In a door latching mechanism, the combination of a latch bolt adapted to be slidably mounted on a door and having an end portion arranged for projection into latching engagement with a keeper member arranged on a door casement, a screw member having a portion bearing under said bolt to lift the same out of latching engagement with said keeper member, a gear carried by said screw member, a gear train for operating said gear to raise said screw member and lift said latch bolt out of latching engagementA with said keeper member including a gear having a socket formed therein for the reception of a key tooperate said gear train, an auxiliary latch member slidably mounted on the latch boit for relative movement and having an end portion adapted for projection into latching engagement with the keeper member labove the said latching end portion of the latch bolt to prevent the latter from being raised by an unauthorized personinto unlatched position, and means for operating said auxiliary latch member.

3. In a door latching mechanism, the combination of a latch bolt adapted to be slidably mounted on a door and having an end portion arranged for projection into latching engagement with akeeper member arranged on a door casement, a screw member having a portion bearing under said bolt to lift the same out of latching engagement with said keepermember, a gear carried by said screw member, a gear train for operating said gear to raise said screw member and lift saidlatch bolt out of latching engagement with said keeper member including a gear having a socket formed 70. therein for the reception of a key to operate said tion of the latch bolt to prevent the latter from being raised by an unauthorized person into unlatched position, and means for operating said auxiliary latch member, said auxiliary member having a rack of teeth formed therein and extending longitudinally of the latch bolt, and the said operating means for the auxiliary latch member including a gear train having a gear in mesh with the said rack.

4. In a door latching mechanism, the combination of a latch bolt adapted to be slidably mounted on a door and having an end portion arranged for projection into latching engagement with a keeper member arranged on a door casement, a screw member having a portion bearing under said bolt to lift the same out of latching engagement with said keeper member, a gear carried by said screw member, a' gear train for operating said gear to raise said screw member and lift said latch bolt out of latching engagement with said keeper member including a gear having a Asocket formed therein for the reception of a key to operate said gear train, an auxiliary latch member. slidably mounted on the latch bolt for movement axially thereof and having an end portion adapted for projection into latching engagement with the keeper member above the said latching end portion of the latch bolt to prevent the latter from being raised by an unauthorized person into unlatched position, and means for operating said auxiliary latch member, said auxiliary member having a rack of teeth formed therein and extending longitudinally of the latch bolt, and the said operati-ng means for the auxiliary latch member including a gear train having a gear in mesh with the said rack, saidoperating means lalso including a gear having a socket for the reception of a key to operate said second-named gear train.

5. In a door latch, a latch bolt movably mounted for latching relation with a iixed keeper-plate, screw means for moving the latch bolt into and out of latching relation with the keeper plate, a member movably associated with the latch bolt for holding the latter in latching relation with the keeper plate, and gear means for operating said member. l l

6. In a door latching device, aA latch bolt adapted to be movably mounted upon a door for latching engagement with a keeper plate, screw means c connectedwith the latch bolt for operating the same, gear means connected with said screw means for moving the latter, a member movably associated with the latch bolt for holding the latter in iixed relation with the keeper plate, gear means for operating said member, a portion of said gear means vbeing arranged in overlapping relation, one of said portions being cut away to permit access to the other portion, to permit an operating device tobe connected with each portion.

'7. In a door latching device, a latch bolt adapted to be slidably mounted on a door and having a porti-on arranged for latching relation with a keeper plate on a door casing, screw means for moving the latch bolt into and out of latching relation with the keeper plate, an auxiliary latching member movably mounted upon the latch bolt for holding the latter in latching relation 7with'the keeper plate, and means for independently operating the screw means and said auxiliary latch member.

' ANTHONY MICHAUKA. 

